I'm currently using Perl scripts to generate these lists. I could certainly share them, however in their current state they're a bit suboptimal for practical, basic use. The reason for this is, that I am working on machine learning code to automate some aspects of moderation. The top-N lists are a byproduct of the initial work that went into the machine-learning code.

The way the code works is as follows:

A nightly script keeps a local mirror of a subreddit up to date.

From that mirror a trivial textual database is created.

From that database the top-N lists are generated.

The reason this code works off of local mirrors is that I need a lot of training data and fast execution time for the machine-learning code. In regard to the top-N lists, this creates the drawback that there's a huge infrastructure for a relatively simple bit of code.

With that said, however, there are some reddits, such as /r/politics, that have so much traffic, that it's impossible to see a whole month in the history. So for the larger subreddits, a local cache is still needed.

Anyways, I could certainly put the code up for you once I get it cleaned up at the end of this month. I just tweaked it to do a top-N list for /r/apple and it's still unfinished. If you don't hear from me in a couple of weeks send me a message to remind me. :)